Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, 26.10.2015
Determination of a turbocharged gasoline engine for hybrid powertrains Agenda Introduction Hybrid Electric Vehicles (HEV) Investigated concept ICE adaption Results Conclusion and future outlook 2 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
Introduction Dynamics of aggregats in hybrid powertrains Cooperation-Professorship: Prof. Dr.-Ing. Michael Bargende Postgraduate: Hr. Felix Kercher Department: Powertrain Concepts Modeling & Simulation Head of Department: Dr.-Ing. Sebastian Grams Project Manager: Dr.-Ing. Michael Auerbach 3 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
Hybrid Electric Vehicles (HEV) Powertrain portfolio degree of electrification conventional powertrain hybrid powertrain full electric powertrain Highly advanced ICEs ICE combined with EM Battery electric vehicles 4 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
Hybrid Electric Vehicles (HEV) Complexity in modern gasoline engines throttle: manifold injection: injection timing injected mass spark plug: spark timing valve train: cam phasing cam profile angle tumble flap: position direct injection: injection timing injected mass wastegate actuator: position gas exchange thermodynamics 5 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
Hybrid Electric Vehicles (HEV) Complexity in modern gasoline engines Throttle angle Approx. 5 different angles Wastegate position Approx. 5 different positions Variable valve timing 15 different intake timings 15 different exhaust timings Variable cam profiles 2 intake profiles Tumble flap position 2 positions Dual mode injection system 2 types (DI or MPI) Approx. 10 different proportionings Variable spark timing Approx. 10 different spark timings Overall about 2.250.000 combinations possible!!! 6 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
Hybrid Electric Vehicles (HEV) How to develop an ICE for a hybrid? Huge development efford needed in order to fit an existing ICE in hybrid powertrains Experimental researches 3D CFD Expensive hardware Large workforce needed Reliable results Complex pre-processing Huge amount of time needed to generate results Quality of results depending on boundary conditions 1D simulation Comprehensive understanding of the system possible Little manpower necessary Quick and reliable results Huge number of variations can easily be handled 7 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
Investigated concept Serial hybrid Minimum of 3 power units required Energy generator (mostly ICE) Electric generator Electric traction motor ICE in serial powertrains Quasistationary operations Engine speed and load are not directly affected by current driving status Generator unit (Energy generator + Electric generator) Efficency depends on perfomance characteristics of the units chemical electric 8 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
degree of specification Investigated concept Development model for a serial hybrid project timeline concept decision experimental validation hardware matching control strategies determination of operating range determination of generator unit efficencies component adaption 9 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
Investigated concept Determination of generator unit operating range 40 to 100% electric power Focus on high generator unit efficiency Overlapping of the separate best points at fixed ratio = 1 Different torque levels of EM and ICE lead to best efficiency for investigated concept Operation at best efficiency for each electric power output 10 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
D = 8 CA 20 percentage points D = 6 CA D = 4 CA Investigated concept Simulation results in ICE operating range Intake Valve Timing 50% Burn Point WG Ratio (m WG /m exh ) Step 3: Fixed valve timing Exhaust Valve Timing Step 1: Increase compression ratio Step 2: Adjusted turbocharger 11 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
ICE adaption 1D model with adaption steps 1. Increased compression ratio 2. Adjusted turbocharger 3. Fixed valve timing 12 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
ICE adaption Step 1: Increase of compression ratio (0.8 units) Efficiency loss due to knock limitation Efficiency increase at optimal 50% burn point 13 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
ICE adaption Step 2: Step 1 + Turbocharger adjustment Decrease of residual gas fraction Overall benefits in efficiency due to lower exhaust gas back pressure 14 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
ICE adaption Step 3: Step 1 + 2 + Fixed valve timing (adjusted) Exhaust valve timing is adjusted to match the new turbocharger 15 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
Results Optimal efficiency operating lines Base Adjusted turbocharger and fixed valve timing lead to reduced low-end-torque Adaption Map range with high efficiencies is widened 16 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
Determination of generator unit efficiencies Base Adaption 17 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
Conclusion and outlook Methodical approaches are needed for the development of future powertrains Power units in hybrid powertrains must be adapted in order to match the desired goals 1D simulation is the prefered tool to handle and evaluate the complexity in internal combustion engines Operating ranges of ICEs in serial hybrids can be significantly reduced Increased efficiency Reduced application effort The combined efficiency of a generator unit in a serial hybrid was raised by 2% over a wide range of electric power 18 Determination of a turbocharged gasoline engine for hybrid powertrains F. Kercher, I/EA-725 26.10.2015
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